1. Field of the Invention
This invention relates in general to a microfiche processing apparatus and in particular to a modular processing apparatus comprising a basic processing module which co-operates with one of several different film advancing modules for processing various types of microfilm.
2. Description of the Prior Art
One form of microfilm is microfiche which is generally known as a group of related images arranged on a card-like transparent sheet of film. Typically, these sheets measure 105 mm by 148 mm and are unmounted. The wide-spread use of microfiche has led to a demand for a means of duplicating the microfiche. However, the use of three major types of duplicating film, silver film, diazo film and vesicular film, requires the utilization of three different developing processes with their associated developing apparatus.
Early microfiche copiers generally comprised two separate machines. In one machine, the master microfiche was exposed in juxtaposition with the copy film. Then the exposed copy film was transferred to a separate developing machine. Although this operation only required one exposure machine and three different developers to handle the three types of film, the manual labor involved in transferring the exposed film to the proper development machine was costly.
Other early attempts combined the exposure and development functions for each type of film in a separate machine. However, this required a substantial investment since three different machines were needed to develop the three types of film and two extra exposure machines were included.
An attempt to reduce the previously mentioned costs produced the microfiche duplicator disclosed in U.S. Pat. No. 3,836,252 issued Sept. 17, 1974. This duplicator combined in a single machine one exposure station and separate diazo and vesicular film developing means. However, this machine was limited in flexibility since only two of the three basic types of film could be developed and it was difficult to add means for developing any other type of film. Furthermore, this machine was more expensive than a duplicator for only one type of film where the capability for duplicating the other type of film was not required.